X-Git-Url: http://git.silcnet.org/gitweb/?a=blobdiff_plain;f=lib%2Fsilccrypt%2Frsa.c;h=7bacd1e098af114fd4663eb4c6b5f9c1720bb3fc;hb=413da0f8686910f5e627393157566ae729ca99c4;hp=5607dfc2db41ca0576ae62ae17f4be263bdddac1;hpb=72cfa31520ebc0058763a30e21c13f6e9a964aa0;p=silc.git

diff --git a/lib/silccrypt/rsa.c b/lib/silccrypt/rsa.c
index 5607dfc2..7bacd1e0 100644
--- a/lib/silccrypt/rsa.c
+++ b/lib/silccrypt/rsa.c
@@ -35,8 +35,9 @@
  *	Decryption:
  *	m = c ^ d mod n
  *
- * This code is based on SSH's (Secure Shell), PGP's (Pretty Good Privacy) 
- * and RSAREF Toolkit's RSA source codes. They all were a big help for me.
+ * The SSH's (Secure Shell), PGP's (Pretty Good Privacy) and RSAREF 
+ * Toolkit were used as reference when coding this implementation. They 
+ * all were a big help for me.
  *
  * I also suggest reading Bruce Schneier's; Applied Cryptography, Second 
  * Edition, John Wiley & Sons, Inc. 1996. This book deals about RSA and 
@@ -60,9 +61,20 @@
      The `tmplen' in encrypt, decrypt, sign and verify PKCS API functions
      is now calculated by (key->bits + 7) / 8.  It is the length of one block.
 
+   o Sat Mar 16 18:27:19 EET 2002  Pekka
+
+     Use the SilcRng sent as argument to SILC_PKCS_API_INIT in prime 
+     generation.
+
+   o Sat Sep 26 19:59:48 EEST 2002  Pekka
+
+     Fixed double free in public key setting.  Use a bit larger e as
+     starting point in key generation.
+
 */
 
 #include "silcincludes.h"
+#include "rsa_internal.h"
 #include "rsa.h"
 
 /*
@@ -73,8 +85,9 @@
 
 SILC_PKCS_API_INIT(rsa)
 {
-  uint32 prime_bits = keylen / 2;
-  SilcInt p, q;
+  SilcUInt32 prime_bits = keylen / 2;
+  SilcMPInt p, q;
+  bool found = FALSE;
 
   printf("Generating RSA Public and Private keys, might take a while...\n");
 
@@ -82,37 +95,38 @@ SILC_PKCS_API_INIT(rsa)
   silc_mp_init(&q);
 
   /* Find p and q */
- retry_primes:
-  printf("Finding p: ");
-  silc_math_gen_prime(&p, prime_bits, TRUE);
-  
-  printf("\nFinding q: ");
-  silc_math_gen_prime(&q, prime_bits, TRUE);
-  
-  if ((silc_mp_cmp(&p, &q)) == 0) {
-    printf("\nFound equal primes, not good, retrying...\n");
-    goto retry_primes;
+  while (!found) {
+    printf("Finding p: ");
+    silc_math_gen_prime(&p, prime_bits, TRUE, rng);
+    
+    printf("\nFinding q: ");
+    silc_math_gen_prime(&q, prime_bits, TRUE, rng);
+
+    if ((silc_mp_cmp(&p, &q)) == 0)
+      printf("\nFound equal primes, not good, retrying...\n");
+    else
+      found = TRUE;
   }
 
   /* If p is smaller than q, switch them */
   if ((silc_mp_cmp(&p, &q)) > 0) {
-    SilcInt hlp;
+    SilcMPInt hlp;
     silc_mp_init(&hlp);
 
     silc_mp_set(&hlp, &p);
     silc_mp_set(&p, &q);
     silc_mp_set(&q, &hlp);
 
-    silc_mp_clear(&hlp);
+    silc_mp_uninit(&hlp);
   }
 
   /* Generate the actual keys */
   rsa_generate_keys((RsaKey *)context, keylen, &p, &q);
 
-  silc_mp_clear(&p);
-  silc_mp_clear(&q);
+  silc_mp_uninit(&p);
+  silc_mp_uninit(&q);
   
-  printf("\nKeys generated succesfully.\n");
+  printf("\nKeys generated successfully.\n");
 
   return TRUE;
 }
@@ -128,11 +142,11 @@ SILC_PKCS_API_GET_PUBLIC_KEY(rsa)
 {
   RsaKey *key = (RsaKey *)context;
   unsigned char *e, *n, *ret;
-  uint32 e_len, n_len;
+  SilcUInt32 e_len, n_len;
   unsigned char tmp[4];
 
   e = silc_mp_mp2bin(&key->e, 0, &e_len);
-  n = silc_mp_mp2bin(&key->n, key->bits / 8, &n_len);
+  n = silc_mp_mp2bin(&key->n, (key->bits + 7) / 8, &n_len);
 
   *ret_len = e_len + 4 + n_len + 4;
   ret = silc_calloc(*ret_len, sizeof(unsigned char));
@@ -167,11 +181,11 @@ SILC_PKCS_API_GET_PRIVATE_KEY(rsa)
 {
   RsaKey *key = (RsaKey *)context;
   unsigned char *e, *n, *d, *ret;
-  uint32 e_len, n_len, d_len;
+  SilcUInt32 e_len, n_len, d_len;
   unsigned char tmp[4];
 
   e = silc_mp_mp2bin(&key->e, 0, &e_len);
-  n = silc_mp_mp2bin(&key->n, key->bits / 8, &n_len);
+  n = silc_mp_mp2bin(&key->n, (key->bits + 7) / 8, &n_len);
   d = silc_mp_mp2bin(&key->d, 0, &d_len);
 
   *ret_len = e_len + 4 + n_len + 4 + d_len + 4;
@@ -214,34 +228,50 @@ SILC_PKCS_API_SET_PUBLIC_KEY(rsa)
 {
   RsaKey *key = (RsaKey *)context;
   unsigned char tmp[4];
-  uint32 e_len, n_len;
+  SilcUInt32 e_len, n_len;
+
+  if (key->pub_set) {
+    silc_mp_uninit(&key->e);
+    silc_mp_uninit(&key->n);
+    key->pub_set = FALSE;
+  }
+
+  if (key_len < 4)
+    return 0;
 
   silc_mp_init(&key->e);
   silc_mp_init(&key->n);
 
   memcpy(tmp, key_data, 4);
   SILC_GET32_MSB(e_len, tmp);
-  if (e_len > key_len) {
-    silc_mp_clear(&key->e);
-    silc_mp_clear(&key->n);
-    return FALSE;
+  if (!e_len || e_len + 4 > key_len) {
+    silc_mp_uninit(&key->e);
+    silc_mp_uninit(&key->n);
+    return 0;
   }
 
   silc_mp_bin2mp(key_data + 4, e_len, &key->e);
-  
+
+  if (key_len < 4 + e_len + 4) {
+    silc_mp_uninit(&key->e);
+    silc_mp_uninit(&key->n);
+    return 0;
+  }
+
   memcpy(tmp, key_data + 4 + e_len, 4);
   SILC_GET32_MSB(n_len, tmp);
-  if (e_len + n_len > key_len) {
-    silc_mp_clear(&key->e);
-    silc_mp_clear(&key->n);
-    return FALSE;
+  if (!n_len || e_len + 4 + n_len + 4 > key_len) {
+    silc_mp_uninit(&key->e);
+    silc_mp_uninit(&key->n);
+    return 0;
   }
 
   silc_mp_bin2mp(key_data + 4 + e_len + 4, n_len, &key->n);
 
-  key->bits = n_len * 8;
+  key->bits = silc_mp_sizeinbase(&key->n, 2);
+  key->pub_set = TRUE;
 
-  return TRUE;
+  return key->bits;
 }
 
 /* Set private key. This derives the public key from the private
@@ -252,7 +282,21 @@ SILC_PKCS_API_SET_PRIVATE_KEY(rsa)
 {
   RsaKey *key = (RsaKey *)context;
   unsigned char tmp[4];
-  uint32 e_len, n_len, d_len;
+  SilcUInt32 e_len, n_len, d_len;
+
+  if (key->prv_set) {
+    silc_mp_uninit(&key->d);
+    key->prv_set = FALSE;
+  }
+
+  if (key->pub_set) {
+    silc_mp_uninit(&key->e);
+    silc_mp_uninit(&key->n);
+    key->pub_set = FALSE;
+  }
+
+  if (key_len < 4)
+    return FALSE;
 
   silc_mp_init(&key->e);
   silc_mp_init(&key->n);
@@ -260,37 +304,56 @@ SILC_PKCS_API_SET_PRIVATE_KEY(rsa)
 
   memcpy(tmp, key_data, 4);
   SILC_GET32_MSB(e_len, tmp);
-  if (e_len > key_len) {
-    silc_mp_clear(&key->e);
-    silc_mp_clear(&key->n);
+  if (e_len + 4 > key_len) {
+    silc_mp_uninit(&key->e);
+    silc_mp_uninit(&key->n);
+    silc_mp_uninit(&key->d);
     return FALSE;
   }
 
   silc_mp_bin2mp(key_data + 4, e_len, &key->e);
   
+  if (key_len < e_len + 4 + 4) {
+    silc_mp_uninit(&key->e);
+    silc_mp_uninit(&key->n);
+    silc_mp_uninit(&key->d);
+    return FALSE;
+  }
+
   memcpy(tmp, key_data + 4 + e_len, 4);
   SILC_GET32_MSB(n_len, tmp);
-  if (e_len + n_len > key_len) {
-    silc_mp_clear(&key->e);
-    silc_mp_clear(&key->n);
+  if (e_len + 4 + n_len + 4 > key_len) {
+    silc_mp_uninit(&key->e);
+    silc_mp_uninit(&key->n);
+    silc_mp_uninit(&key->d);
     return FALSE;
   }
 
   silc_mp_bin2mp(key_data + 4 + e_len + 4, n_len, &key->n);
 
+  if (key_len < e_len + 4 + n_len + 4 + 4) {
+    silc_mp_uninit(&key->e);
+    silc_mp_uninit(&key->n);
+    silc_mp_uninit(&key->d);
+    return FALSE;
+  }
+
   memcpy(tmp, key_data + 4 + e_len + 4 + n_len, 4);
   SILC_GET32_MSB(d_len, tmp);
-  if (e_len + n_len + d_len > key_len) {
-    silc_mp_clear(&key->e);
-    silc_mp_clear(&key->n);
+  if (e_len + 4 + n_len + 4 + d_len + 4 > key_len) {
+    silc_mp_uninit(&key->e);
+    silc_mp_uninit(&key->n);
+    silc_mp_uninit(&key->d);
     return FALSE;
   }
 
   silc_mp_bin2mp(key_data + 4 + e_len + 4 + n_len + 4, d_len, &key->d);
 
-  key->bits = n_len * 8;
+  key->bits = silc_mp_sizeinbase(&key->n, 2);
+  key->prv_set = TRUE;
+  key->pub_set = TRUE;
 
-  return TRUE;
+  return key->bits;
 }
 
 SILC_PKCS_API_CONTEXT_LEN(rsa)
@@ -298,55 +361,18 @@ SILC_PKCS_API_CONTEXT_LEN(rsa)
   return sizeof(RsaKey);
 }
 
-SILC_PKCS_API_DATA_CONTEXT_LEN(rsa)
-{
-  return sizeof(RsaDataContext);
-}
-
-SILC_PKCS_API_SET_ARG(rsa)
-{
-  RsaDataContext *data_ctx = (RsaDataContext *)data_context;
-
-  switch(argnum) {
-  case 1:
-    data_ctx->src = val;
-    return TRUE;
-    break;
-  case 2:
-    data_ctx->dst = val;
-    return TRUE;
-    break;
-  case 3:
-    data_ctx->exp = val;
-    return TRUE;
-    break;
-  case 4:
-    data_ctx->mod = val;
-    return TRUE;
-    break;
-  default:
-    return FALSE;
-    break;
-  }
-
-  return FALSE;
-}
-
 SILC_PKCS_API_ENCRYPT(rsa)
 {
   RsaKey *key = (RsaKey *)context;
-  int i, tmplen;
-  SilcInt mp_tmp;
-  SilcInt mp_dst;
+  int tmplen;
+  SilcMPInt mp_tmp;
+  SilcMPInt mp_dst;
 
-  silc_mp_init_set_ui(&mp_tmp, 0);
-  silc_mp_init_set_ui(&mp_dst, 0);
+  silc_mp_init(&mp_tmp);
+  silc_mp_init(&mp_dst);
 
   /* Format the data into MP int */
-  for (i = 0; i < src_len; i++) {
-    silc_mp_mul_2exp(&mp_tmp, &mp_tmp, 8);
-    silc_mp_add_ui(&mp_tmp, &mp_tmp, src[i]);
-  }
+  silc_mp_bin2mp(src, src_len, &mp_tmp);
 
   /* Encrypt */
   rsa_en_de_crypt(&mp_dst, &mp_tmp, &key->e, &key->n);
@@ -354,14 +380,11 @@ SILC_PKCS_API_ENCRYPT(rsa)
   tmplen = (key->bits + 7) / 8;
 
   /* Format the MP int back into data */
-  for (i = tmplen; i > 0; i--) {
-    dst[i - 1] = (unsigned char)(silc_mp_get_ui(&mp_dst) & 0xff);
-    silc_mp_fdiv_q_2exp(&mp_dst, &mp_dst, 8);
-  }
+  silc_mp_mp2bin_noalloc(&mp_dst, dst, tmplen);
   *dst_len = tmplen;
 
-  silc_mp_clear(&mp_tmp);
-  silc_mp_clear(&mp_dst);
+  silc_mp_uninit(&mp_tmp);
+  silc_mp_uninit(&mp_dst);
 
   return TRUE;
 }
@@ -369,18 +392,15 @@ SILC_PKCS_API_ENCRYPT(rsa)
 SILC_PKCS_API_DECRYPT(rsa)
 {
   RsaKey *key = (RsaKey *)context;
-  int i, tmplen;
-  SilcInt mp_tmp;
-  SilcInt mp_dst;
+  int tmplen;
+  SilcMPInt mp_tmp;
+  SilcMPInt mp_dst;
 
-  silc_mp_init_set_ui(&mp_tmp, 0);
-  silc_mp_init_set_ui(&mp_dst, 0);
+  silc_mp_init(&mp_tmp);
+  silc_mp_init(&mp_dst);
 
   /* Format the data into MP int */
-  for (i = 0; i < src_len; i++) {
-    silc_mp_mul_2exp(&mp_tmp, &mp_tmp, 8);
-    silc_mp_add_ui(&mp_tmp, &mp_tmp, src[i]);
-  }
+  silc_mp_bin2mp(src, src_len, &mp_tmp);
 
   /* Decrypt */
   rsa_en_de_crypt(&mp_dst, &mp_tmp, &key->d, &key->n);
@@ -388,14 +408,11 @@ SILC_PKCS_API_DECRYPT(rsa)
   tmplen = (key->bits + 7) / 8;
 
   /* Format the MP int back into data */
-  for (i = tmplen; i > 0; i--) {
-    dst[i - 1] = (unsigned char)(silc_mp_get_ui(&mp_dst) & 0xff);
-    silc_mp_fdiv_q_2exp(&mp_dst, &mp_dst, 8);
-  }
+  silc_mp_mp2bin_noalloc(&mp_dst, dst, tmplen);
   *dst_len = tmplen;
 
-  silc_mp_clear(&mp_tmp);
-  silc_mp_clear(&mp_dst);
+  silc_mp_uninit(&mp_tmp);
+  silc_mp_uninit(&mp_dst);
 
   return TRUE;
 }
@@ -403,18 +420,15 @@ SILC_PKCS_API_DECRYPT(rsa)
 SILC_PKCS_API_SIGN(rsa)
 {
   RsaKey *key = (RsaKey *)context;
-  int i, tmplen;
-  SilcInt mp_tmp;
-  SilcInt mp_dst;
+  int tmplen;
+  SilcMPInt mp_tmp;
+  SilcMPInt mp_dst;
 
-  silc_mp_init_set_ui(&mp_tmp, 0);
-  silc_mp_init_set_ui(&mp_dst, 0);
+  silc_mp_init(&mp_tmp);
+  silc_mp_init(&mp_dst);
 
   /* Format the data into MP int */
-  for (i = 0; i < src_len; i++) {
-    silc_mp_mul_2exp(&mp_tmp, &mp_tmp, 8);
-    silc_mp_add_ui(&mp_tmp, &mp_tmp, src[i]);
-  }
+  silc_mp_bin2mp(src, src_len, &mp_tmp);
 
   /* Sign */
   rsa_en_de_crypt(&mp_dst, &mp_tmp, &key->d, &key->n);
@@ -422,14 +436,11 @@ SILC_PKCS_API_SIGN(rsa)
   tmplen = (key->bits + 7) / 8;
 
   /* Format the MP int back into data */
-  for (i = tmplen; i > 0; i--) {
-    dst[i - 1] = (unsigned char)(silc_mp_get_ui(&mp_dst) & 0xff);
-    silc_mp_fdiv_q_2exp(&mp_dst, &mp_dst, 8);
-  }
+  silc_mp_mp2bin_noalloc(&mp_dst, dst, tmplen);
   *dst_len = tmplen;
 
-  silc_mp_clear(&mp_tmp);
-  silc_mp_clear(&mp_dst);
+  silc_mp_uninit(&mp_tmp);
+  silc_mp_uninit(&mp_dst);
 
   return TRUE;
 }
@@ -437,28 +448,22 @@ SILC_PKCS_API_SIGN(rsa)
 SILC_PKCS_API_VERIFY(rsa)
 {
   RsaKey *key = (RsaKey *)context;
-  int i, ret;
-  SilcInt mp_tmp, mp_tmp2;
-  SilcInt mp_dst;
+  int ret;
+  SilcMPInt mp_tmp, mp_tmp2;
+  SilcMPInt mp_dst;
 
-  silc_mp_init_set_ui(&mp_tmp, 0);
-  silc_mp_init_set_ui(&mp_tmp2, 0);
-  silc_mp_init_set_ui(&mp_dst, 0);
+  silc_mp_init(&mp_tmp);
+  silc_mp_init(&mp_tmp2);
+  silc_mp_init(&mp_dst);
 
   /* Format the signature into MP int */
-  for (i = 0; i < signature_len; i++) {
-    silc_mp_mul_2exp(&mp_tmp2, &mp_tmp2, 8);
-    silc_mp_add_ui(&mp_tmp2, &mp_tmp2, signature[i]);
-  }
+  silc_mp_bin2mp(signature, signature_len, &mp_tmp2);
 
   /* Verify */
   rsa_en_de_crypt(&mp_dst, &mp_tmp2, &key->e, &key->n);
 
   /* Format the data into MP int */
-  for (i = 0; i < data_len; i++) {
-    silc_mp_mul_2exp(&mp_tmp, &mp_tmp, 8);
-    silc_mp_add_ui(&mp_tmp, &mp_tmp, data[i]);
-  }
+  silc_mp_bin2mp(data, data_len, &mp_tmp);
 
   ret = TRUE;
 
@@ -466,9 +471,9 @@ SILC_PKCS_API_VERIFY(rsa)
   if ((silc_mp_cmp(&mp_tmp, &mp_dst)) != 0)
     ret = FALSE;
 
-  silc_mp_clear(&mp_tmp);
-  silc_mp_clear(&mp_tmp2);
-  silc_mp_clear(&mp_dst);
+  silc_mp_uninit(&mp_tmp);
+  silc_mp_uninit(&mp_tmp2);
+  silc_mp_uninit(&mp_dst);
 
   return ret;
 }
@@ -477,16 +482,14 @@ SILC_PKCS_API_VERIFY(rsa)
    to compute the modulus n has to be generated before calling this. They
    are then sent as argument for the function. */
 
-void rsa_generate_keys(RsaKey *key, uint32 bits, 
-		       SilcInt *p, SilcInt *q)
+void rsa_generate_keys(RsaKey *key, SilcUInt32 bits, 
+		       SilcMPInt *p, SilcMPInt *q)
 {
-  SilcInt phi, hlp;
-  SilcInt div, lcm;
-  SilcInt pm1, qm1;
+  SilcMPInt phi, hlp;
+  SilcMPInt div, lcm;
+  SilcMPInt pm1, qm1;
   
   /* Initialize variables */
-  silc_mp_init(&key->p);
-  silc_mp_init(&key->q);
   silc_mp_init(&key->n);
   silc_mp_init(&key->e);
   silc_mp_init(&key->d);
@@ -500,22 +503,18 @@ void rsa_generate_keys(RsaKey *key, uint32 bits,
   /* Set modulus length */
   key->bits = bits;
 
-  /* Set the primes */
-  silc_mp_set(&key->p, p);
-  silc_mp_set(&key->q, q);
-  
   /* Compute modulus, n = p * q */
-  silc_mp_mul(&key->n, &key->p, &key->q);
+  silc_mp_mul(&key->n, p, q);
   
   /* phi = (p - 1) * (q - 1) */
-  silc_mp_sub_ui(&pm1, &key->p, 1);
-  silc_mp_sub_ui(&qm1, &key->q, 1);
+  silc_mp_sub_ui(&pm1, p, 1);
+  silc_mp_sub_ui(&qm1, q, 1);
   silc_mp_mul(&phi, &pm1, &qm1);
   
   /* Set e, the public exponent. We try to use same public exponent
      for all keys. Also, to make encryption faster we use small 
      number. */
-  silc_mp_set_ui(&key->e, 127);
+  silc_mp_set_ui(&key->e, 65533);
  retry_e:
   /* See if e is relatively prime to phi. gcd == greates common divisor,
      if gcd equals 1 they are relatively prime. */
@@ -525,17 +524,17 @@ void rsa_generate_keys(RsaKey *key, uint32 bits,
     goto retry_e;
   }
   
-  /* Find d, the private exponent. */
+  /* Find d, the private exponent, e ^ -1 mod lcm(phi). */
   silc_mp_gcd(&div, &pm1, &qm1);
-  silc_mp_fdiv_q(&lcm, &phi, &div);
+  silc_mp_div(&lcm, &phi, &div);
   silc_mp_modinv(&key->d, &key->e, &lcm);
   
-  silc_mp_clear(&phi);
-  silc_mp_clear(&hlp);
-  silc_mp_clear(&div);
-  silc_mp_clear(&lcm);
-  silc_mp_clear(&pm1);
-  silc_mp_clear(&qm1);
+  silc_mp_uninit(&phi);
+  silc_mp_uninit(&hlp);
+  silc_mp_uninit(&div);
+  silc_mp_uninit(&lcm);
+  silc_mp_uninit(&pm1);
+  silc_mp_uninit(&qm1);
 }
 
 /* Clears whole key structure. */
@@ -543,11 +542,12 @@ void rsa_generate_keys(RsaKey *key, uint32 bits,
 void rsa_clear_keys(RsaKey *key)
 {
   key->bits = 0;
-  silc_mp_clear(&key->p);
-  silc_mp_clear(&key->q);
-  silc_mp_clear(&key->n);
-  silc_mp_clear(&key->e);
-  silc_mp_clear(&key->d);
+  if (key->pub_set) {
+    silc_mp_uninit(&key->n);
+    silc_mp_uninit(&key->e);
+  }
+  if (key->prv_set)
+    silc_mp_uninit(&key->d);
 }
 
 /* RSA encrypt/decrypt function. cm = ciphertext or plaintext,
@@ -558,8 +558,8 @@ void rsa_clear_keys(RsaKey *key)
    Decrypt: m = c ^ d mod n 
 */
 
-void rsa_en_de_crypt(SilcInt *cm, SilcInt *mc, 
-		     SilcInt *expo, SilcInt *modu)
+void rsa_en_de_crypt(SilcMPInt *cm, SilcMPInt *mc, 
+		     SilcMPInt *expo, SilcMPInt *modu)
 {
-  silc_mp_powm(cm, mc, expo, modu);
+  silc_mp_pow_mod(cm, mc, expo, modu);
 }